Control-fed, ethanol-fed, and ethanol withdrawn rats were intravenously injected with 9 mCi/kg NaH14CO3 and killed at various times up to 48 hours following injection. Livers were stored at -70 degrees C. CYP2E1 was immunopurified from liver microsomal preparations. Microsomal preparations were also assayed for enzyme activity CYP2E1 content.